Thermostatic valve mechanism



F. W. ROBERTSHAW ET AL May l5, i923.

THERMOSTATIC VALVE MECHANISM Wiled Jan. 20. 1921 4 Sheets-Sheet l May15, i923.

F. W. ROBERTSHAW ET AL THERMOSTATIC VALVE MECHANI SM Filed Jan. 20. 19214 SheetsjSheet 2 3.9 A 1 mm :5 4@ 47 INVENTORS xmwwu May mm3. M5566@ F.W. ROBERTSHAW ET AL THERMOSTATIC VALVE MECHANISM Filed Jan, 20, 1921 4Sheets-Sheet 3 4a 19a 15a Vu l M 52a A h 17@ JE 2a f1 l l I lNvEwronPatented May 115, 1923 UNH STATE TET @FMCG FREDERICK W. ROBERTSHAW, OFPITTSBURGH, AND GEORGE A. ROBERTSHAW, OF GREENSBURG, PENNSYLVANIA.

THERMOSTATIC VALVE MECHANISM.

Application led January 20, 1921.

To all whom t may concern.'

Be it known that we, FREDERICK W. RoBnR'rsHAw, a resident of Pittsburgh,in the county of Allegheny and State of ennsylvania, and GEORGE A.RoBnRTsHAw, a resident of Greensburg, in the county of lVest-morelandand State of Pennsylvania, have invented a new and useful lmprovement inThermostatic Valve Mechanism, of which the following is a full, clear,and exact description, reference being had to the accompanying drawings,in which- Figure l is a vertical section illustrating one form ofapparatus embodying our invention.

Figure 2 is a similar view showing another embodiment of the invention.

Figure 3 is a side elevation showing still another embodment of theinvention.

Figure 4 is a view similar to Figure 2, and showing anothermodification.

Our invention has relation to thermo- 'static valve mechanismparticularly designed for the control of the supply of gas or of air andgas to a gas burner or burners, although it may be utilized for thecontrol of other fluids.

One object of our invention is to provide mechanism of this characterwhich'will insure a quick opening of the main valve which controls theHow through the supply line of the system. X

A further object of the invention, as embodied in a preferred formthereof, is to provide a novel arrangement of the pilot light i gassupply whereby a constant blue flame may be provided at the pilot light,receiving its-supply of gas from the relief or bleeding ports of thevalve system.

The particular nature of our invention will be best understood byreference to the accompanying drawings, in which we lhave shown severaldifl'erent embodiments thereof, which will now be described, it beingpremised, however, that the invention is susceptible of various otherembodiments and may be changed in various ways within the spiritand'scope of the appended claims.

Referring iirst to thatform of our invention which is illustrated inFigure 1, the numeral 2 designates a main gas supply pipe, 3 a maindiaphragm chamber, 4 an auxiliary diaphragm chamber, and 5 athermostatic element which is so arranged as to be ar"- ected by changesin temperature in the heat- Serial No. 438,738.

ing system controlled by the mechanism. The supply pipe 2 has a port 6leading into the lower part of the diaphragm chamber 3, with which itcommunicates by means of a port 7 having a valve seat 8 at its upperside. This/,port is controlled by a main valve 9 carried by a flexiblediaphragm 10 in the chamber 3. 12 is an outlet from the lower portion ofthe chamber 3 and leading to the burner or burners to be supplied andcontrolled (not shown).

rllhe pipe 2 is also connected by a port 13 with the lower portion ofthe diaphragm chamber 4, the opening in the said chamber beingcontrolled by an auxiliary valve 14 carried by a flexible diaphragm 15in said chamber 4, the valve havingxa seat at 16.

`17 is a port, constituting at times a relief passage, connecting thelower part of the chamber 4 with the upper part of the chamber 3.y 18 isan escape or relief passage leading from the lower portion of thechamber 4 into a pipe 19 which is connected to a gas and air mixer 20for supplying a pilot light connection 21.

22 designates any suitable valve arranged to be opened by the action ofthe thermostatic element 5 and to be closed by the spring 23 acting inopposition to said element. rlhe valve 22 is seated in the chamber 24,which is connected above the valve by a connection 25 leading tothe gassupply pipe 2. The lower portion of the chamber 24 is connected bya pipeor passage 26 with the upper portion of the diaphragm chamber 4. A pipe2T also leads outwardly from the lower portion of the chamber 24 andinto the mixer 2O of the pilot light. The gas enters the mixer 2O fromthe pipes 19 and 27 by means of the respective nozzles 28 and 29, whichare directed at an angle'to each other. indicates any suitableregulating device for the port 6.

rlhe operation is as follows: `With the i ting gas into the lowerport-ion of thechambei-424 from the pipe 2, this gas; passingv throughthe connection 26 into the upper portion ot' the diaphragm chamber' -4(the valve 14 being open), builds up a pressure in said chamber abovethe diaphragm 15, thereby closing the valve 14 and cutting off vthesupply. of gas through the port 13 into the lower portion of saidchamber 4, which gas has, by reason of the port 17, been acting tomaintain a closing control at the upper side of the diaphragm 10. Assoon as the valve 14 closes, no more gas can enter the lower part of thechamber 4 or the upper part of the chamber 3; and the gas which iscontained in these portionsof the two chambers escapes through the port18 and pipe 19 tol the` pilot li ht. This reduction of pressure abovethe (Iiaphragm 10 occurs very rapidly, owing to the comparatively smallarea of the upper portion of this chamber; and the diaphragm 10,- beingexposed to the iow pressure of the gas from the supply pipe 2 at itsunder side, will open quickly, thereby admitting immediately asubstantially full supply of gas to the burners. It Will be noted thatthe valve 9 requires but* a relatively small opening movement to yprovide a free passage for the as of an area equal to the area of theport During the time that the valves 9 and 22 have been closed, thepilot light has been receiving its supply of gas from the lower portionof the diaphragm chamber through the relief port 18. When this supply iscut off by the closing of the valve 14 (except for the further leakagewhich occurs in the diaphragm chambers), the valve 22 has been openedand the ilot light is receiving a supply through t e pipe 27.

After the operations above described have taken place, the valve 9remains opten so long as thetemperature in the heater does not exceedthe predetermined maximum for which the therinostatic element isadjusted. When such maximum is reached, the valve' 22 again closes,thereby shutting off any further entrance of gas through the pipe 26into the upper portion of the diaphragm chamber 4. The as which ispresent in the upper portion of tis chamber escapes through the pipes 26and 27, thereby relieving pressure above the diaphragm 15 and allowingsaid V diaphragm to open under the action of the gas entering .below thevalve through the port 13. The opening of the valve 14 again permits gasto flow through the po-rt 17 into the upper portion of the diaphragmchamber 3, thereby establishing therein a :pressure suficient to againclose the valve 9.

In .the modification shown in Figure 2,31 designates the main gasvsupply pipe, and 32 is the main valve controlling the fiow to the burnerconnection 31. 33 is the main diaphragm chamber having there-in aflexible diaphragm 34 to which is connected the stem 35 of the y valve32. 36 is a spring tending to seat the valve 32 against the action ofthe diaphragm 34. 37 is the auxiliaryi .diaphragm chamber having thereina @gas supply pipe 31 to the lower side of the diaphragm chamber 37, andcorresponding to the connection 13 of Figure 1. 46is a connectionbetween the lower portion of the diaphragm chamber 37 and the upperportion of the diaphragm chamber 33, and corresponding in function tothe port 17 of `Figure 1. 47 is a relief pipe leading from theconnection 46, and corresponding in function to the port 18 and pipe 19of Figure 1.

In this form of our invention the upper and lower portions of thediaphragm chainber 38 are in constant communication with each otherthrough a small orifice 48, which is formed through the valve 39.

- In Figure 2 the parts are shown in the position which they occupy whenthe main valve 32 is closed to cut off the supply 4of gas to theburners. Under these conditions the connection between the pipes 42 and44 is closedv at the valve 41; and the pressure in the upper part of thediaphragm chamber 37 will vhold the valve 39 closed by reason of thelarger effective area of the upper surface of the diaphragm. y The spaceabove the diaphragm 34 has been exhausted through the relief connections46 and 47, and the spring 36 is therefore holding the valve 32 l closed.When the temperature in the heater falls to the pre-determined limit,the valve 41 will open, thereby relieving the pressure above thediaphragm 38 andf causing the valve 39 to open. This admits pressurethrough the connections 45 and 46 to the upper side of the diaphragm 34,and builds up a pressure which will open the valve 32. When thetemperature again reaches the maximum Ito which the thermostat is set,the

valve 41 will close and pressure will be built up above the diaphragm 38lthrough the orifice 48 to again close the valve 39 and thereby e'ectthe closure of the valve 32.

In thel form of our invention shown in Figure 2, the reliefs are notadapted to form a constant supply for a pilot light, but the gasescaping therethrough may be burned at the pilot light. i

The form of our invention shown in Figure 3 is generally similar to thatshown in Figure 1. In this figure, however, we have shown the inventionapplied to la system of burners 49 for a heater 50 in which the Cilthermostatic element 5a is placed. We have also shown the-valve 22,which corresponds to the valve 22 of Figure l, as being actuated by amultiple lever 51 which is acted upon by the thermostat. ln this figureWe have also shown the two diaphragm chambers' as separated instead ofbeing placed close together as in Figure l. We have applied to the partsshown in this gure the same reference characters as are applied to thecorresponding parts shown in Figure l, but with the letter a aiixedthereto. |The operation is substantially the same as that of theapparatus shown in Figure l. From a structural standpoint, however, itis less desirable than that shown in Figure l, owing to the greaternumber of ttings and couplings required to connect up the various partsof the apparatus.

lt will be readily understood that by reversing the valve in thediaphragm chamber 3a with respect to its seat, the system may be made tooperate with a reverse action thermostat; that is to say, with athermostat which will act to open the thermostatically controlled valveon a rise in temperature, instead of closing such valve.

ln Figure 4c we have shown our invention as applied to the control ofboth air and gas for supplying a blast burner.l The arrangement is thesame as in Figure 2, but an air valve 52, arranged to control the flowof air through an air supply pipe 53 leading to a burner-pipe 54, hasits stern 55 arranged to be operated by the stem of the gas valve 32a.As will be readily seen, the

ltwo valves 321and 52 will be opened and.

closed in unison. l

lt will be obvious also` that the valve 32a may be the air controlvalve, and the valve 52 the gas controlvalve. ln that case the diaphragmcontrol is effected by air instead of by gas.

:Parts in Figure 4 corresponding to similar parts in Figure 2 are giventhe same reference numerals as in .Figure 2, but with the letter aaixed.

The advantages of our invention result from the provision of theauxiliary diaphragm chamber, diaphragm, and auxiliary valve actuated bythe auxiliary diaphragm. An objection to thermostatically controlleddiaphragm valves such as heretofore used for the control of gas burnersconsisted in the fact that such valves do not always open with suiicientrapidity. When the valve opens slowly, there is a relatively small iiowof gas to the burners, and this often results in the burners lightingback at the mixers. We have discovered that by providing an auxiliarydiaphragm and valve for the purpose of controlling the main diaphragmand valve, this objection can be entirely eliminated.

The form of 'our invention shown in Figures l and 3 is also advantageousin that it enables the pilot light to be operated continuously by thegas which escapes through the relief ports which are necessary totheoperation of the valves.

lWe claim:

l. rl`hermostatic valve mechanism, comprising a Huid pressure supplyline having a branch connection, a thermostatically controlled valve insaid connection, a main valve in said line, both of said valves whenopen being adapted to have a pressure flow therethrough, an actuatingdiaphragm for the main valve, an auxiliary valve, an actuating diaphragmor the auxiliary valve, and connections controlled by the auxiliaryvalve for controlling the action of the main valve, both of saiddiaphragme being operated by the pressure in said supply line,substantially as described.

2. Thermostatic valve mechanism, comprising a main supply pipe, a maincontrol valve for said pipe, a diaphragm for actuating said main controlvalve, an auxiliary valve, an actuating diaphragm for said auxiliaryvalve, connections controlled by the auxiliary valve for controlling thepressure from said supply pipe to one side of said first mentioneddiaphragm, and thermostatically controlled means for directing pressurefrom said pipe to said second mentioned diaphragm, substantially asdescribed.

3. Thermostatic valve mechanism comprising a main supply pipe, a maincontrol valve in said pipe, a diaphragm for actuating the main controlvalve, an auxiliary valve, a diaphragm for actuating the saine,connections controlled by the auxiliary valve for controlling thepressure at one side of the first named diaphragm, thermostatic meansfor controlling the pressure conditions at one side of the auxiliarydiaphragm, relief connections for the chambers ofthe two diaphragms, anda pilot burner connected to receive a supplyy from said reliefconnections substantially as described.

4. rll`hermostatic valve mechanism comprising a .main diaphragm chamber,an auxiliary diaphragm chamber, a main flow passage through the maindiaphragm chamber, an auxiliary flow passage through the auxiliarydiaphragm chamber and Jr'rom thence into the main diaphragm chamber, adiaphragm actuated valve in each of said chambers for controlling theflow therethrough, and thermostatic means for controlling the pressureconditions in the auxiliary diaphragm chamber, substantially asdescribed.

5. Thermostatic valve mechanism' comprising a main diaphragm chamber, amain flow passage leading through said chamber, a diaphragm in saidchamber, a valve*l actuated by said diaphragm and controlling saidpassage, an auxiliary diaphragm chamber having a flow passagetherethrough, a diaphragm in the auxiliary chamber, a Valve actuated bysaid diaphragm for controlling the How passage through the auxiliarychamber, a passage connecting the tWo chambers at opposite sides oftheir respective ldi'- aphragms, and thermostatically controlled meansfor controlling the pressure in the auxiliary chamber at the oppositeside of the diaphragm from that at which the last named connection islocated, substantially as described.

6. Thermostatic valve mechanism comprising a main valve, a fluidpressure supply line 'controlled thereby, a diaphragm' for actuating themain valve by the pressure in said supply line, an auxiliary valve forcontrolling the operation of the main valve, and a thermostaticallyoperated valve for controlling the operation of the auxiliary valve bydirecting pressure thereto from said supply line, substantially asdescribed.

7. Thermostatic valve mechanism comprising a main valve, an auxiliaryvalve for controlling the action of the main valve, a diaphragm chamberand a diaphragm therein for each of said Valves, said chambers havingrelief passages, and a pilot burner to Which both of said reliefpassages are connected, substantially as described.

8. Thermostatic valve mechanism comprising a main valve, an auxiliaryValve for controlling the action of the main valve, a diaphragm chamberand a diaphragm therein for each of said valves, said chambers havingrelief passages, a gas and air mixer into which the iuid from saidrelief passages is arranged to How, and a pilot burner Supplied by saidmixer, substantially as described.

operation of the main valve, and'thermostatic means for controlling theoperation of the auxiliary Valve, together with a second main valvearranged to be controlledv by the first named main valve, substantiallyas described.

l0. The combination With a main. gas

control valve, and a main air control valve,

said valves being arranged to operate in unison, a diaphragm foractuating one of said main valves, an auxiliary valve for controllingsaid diaphragm, a diaphragm for controlling the auxiliary valve, andthermostatic means for controlling the second named diaphragm,substantially as described.

ll. In a thenmostatic valve mechanism, a. main valve, an auxiliary Valvecontrolling the action of the main valve, a diaphragm chamber and adiaphragm therein for each of said valves, said chambers 'having reliefpassages, a mixing chamber With which said relief passages communicate,and a pilot burner supplied by said mixing chamber, substantially asdescribed.

12. Inv a thermosta-tic valve mechanism, a main supply pipe, a maincontrol valve in said pipe, a diaphragm for actuating the main controlvalve, an auxiliary valve, a diaphragm for actuating the same,connections controlled by the auxiliary valve` forY controlling thepressure at one side yof the first named diaphragm, thermostatic meansfor controlling the pressure conditions at one side of the second nameddiaphragm, relief connections for the chambers of said diaphragms, amixing chamber' communicating With said connections and a pilot burnerreceiving' a supply from said mixing chamber, substantially asdescribed.

In testimony whereof We have hereunto set our hands.

FREDERICK lV. ROBERTSHAV. GEORGE A. ROBERTSHAVV.

